( 233 ) 



On the Characters and Affinities of certain Genera, chiFf^'6ei 

 hnging to the Flora Peruviana. By Mr David Don, Li- 

 brarian of the Linnean Society ; Member of the Imperial 

 Academy Naturae Curiosorum ; of the Imperial Society of 

 Naturalists of Moscow ; of the Royal Botanical Society of 

 llatisbon ; and of tl)e Wernerian Society of Edinburgh, &(&*'■' 



. -(Continued from No. for Oct. 1831, p. 280.) "'•*^ 



'^< < 

 ZIGADENUS, Mdi. ^ 



Syst. Linn. HEXANDRIA TRIGYNIA. 

 Ord. Nat. MELANTHACEiE, jBr. 



Perianthium (J-partitum : segmentis lanceolatis, acuminatis, basi biglandulosis. 

 Filamenta subulata, basi dilalata. Antherce reniformes, biloculares: loculis 

 confluentibus. Ovarium (e folliculis 3 connatis compositum) triloculare : 

 ovulis indefinitis. Stigmata simplicia, canaliculata, pruinosa, recurvata. 

 Capsula membranacea, trigona, 3.1ocularis : loculis di-polyspermis. Se- 

 mina adscendentia, complanata, basi parum alata: testa membranaced, 

 laxa, nucleo ejusdem majori. 



Herbae (Amer. Septentr.) caulibus ramosis. Folia lineari-lanceolata, acurriu 

 nata, nervosa, marginihus carinaque scabris. Racemus divisuSf paniculatuSf 

 bracteatus. 



1. Z.frigidu^, ovario semiinfero ! loculis poljspermis, stylis solutis abbre- 



viatis. 



Veratrum frigidum, Deppe et Schiede in SchJecht. Linmsa, 6. p. 46. 

 Ytzcuimpatli tertia, Hernand. Mex. p. 307. 



Hab. In pratis elevatis Orizabae moiitis, alt. 10,000 ped. — Schiede et 

 Deppe. y. (V. s. sp. in Herb. Lamb.) 



Rhizoma bulbo-tuber ovato-oblongum, foliorum emarcidorum rudimentis ves- 

 titum. Caulis erectus, ramosus, teres, laevis, viridis, fere omninb solidus, 

 bi- V. tripedalis, calami scriptorii crassitie. Folia radicalia linearia, acuta, 

 conduplicata, glabra, margine membranacea, minutissime crenulata, re- 

 curvato-patentia, nervis plurimis parallelis striata, pedalia v. ultrh, basi 

 valde dilatata; caulina breviora, erecta; superiora adpressa. Racemus 

 elongatus, paniculatus. Flores albi. Bracteee lanceolatae, acuminatae, 

 membranaceae, basi cucuUata ])edunculos vaginantes, iisdemque longiores. 



Perianthium 6-partitiim, basi turbinata adhaerens : laciniis lanceolatis, acutis, 

 aequalibus. Stamina 6, perianthii laciniis opposita : filamenta subulata, 

 complanata, glabra, basi dilatata atque in annulum brevissimum con- 

 nata : anthercB reniformes, biloculares : loculis confluentibus, rimi undi- 

 que dehiscentibus. Ovarium semi-inferum ! e folliculis 3 conflatum : 

 ovulis indefinitis. Stpli 3, compressi, distincti, recurvati, glabri, breves. 

 Stigmata cucuUata, pruinosa. Capsula ovata, membranacea, S-locularis: 

 loculis polyspermis. Semina compressa, scobiformia, margine altero trun- 

 cate : test& l&xsi, tenuissim^ membranacea. 



This genus is so closely allied to the following, that, besides 

 the glands at the base of the segments of the perianthium, and the 

 branched inflorescence, there is little else to separate them. The 

 species is well distinguished by its half-inferior ovarium, and 

 by the shorter and unconnected styles. 



